If you are familiar with CSS, you can get some browser add-ons that allow you to override the styles on specific websites. Then you can specify your own colors, etc.
For Chrome, there's Stylebot:
https://chrome.google.com/webstore/deta ... eoha?hl=en
It may have been this plugin or something else where someone shared a different lds.org definition on the social page. I used it because I was frustrated with some lds.org things and a kind person on the forums published some other style definitions. The repository on Stylebot is down, so you can't go looking there. If you find a plugin like this that allows community definitions, you might make changes and share with others. Note that with the church domain change (ChurchOfJesusChrist.org vs. lds.org), if you're looking for style definitions anyone else has done, you might have to look under both domains. I also seem to remember finding some anti-church styles on style repository I visited years ago, so be warned. I never tried them out to see how they modified the church website, but they existed.